1. Field of the Invention
The present invention relates to the general technical field of agricultural machinery and relates more specifically to a boom according to the preamble of claim 1.
2. Discussion of the Background
Document FR 2 673 355 describes a spray boom comprising an end section connected to an intermediate section by an articulation made up of a ball joint, of a guide rail and of pins. Upon contact with an obstacle, such an articulation advantageously allows said end section to move away laterally or upward. Once the obstacle has been passed, said end section is returned to its initial position using a draw-spring.
This known safety device does, however, have one drawback. This is that during work, the boom experiences shakes due, for example, to the bumps in the terrain that is to be treated. In order to keep said end section in its initial position, said draw-spring has therefore to exert a relatively high holding force.
In addition, upon contact with an obstacle, the pivoting of said end section with respect to said intermediate section has the effect of lengthening said draw-spring. The return force thus created adds to the initial holding force. Once the obstacle has been passed, the end section is therefore returned violently to its initial position. The boom therefore experiences knocks which, in the long term, are damaging.